I was looking for some advice if possible. I'm a highland piper only but have been offered a set of Uilleann pipes that are supposedly made by John Addison. I have no idea of what to look for or potential value so wondered if anyone would have the time to give me some advice. Here's the only picture I have of them so far:

Ran the photo through one of my graphics programs to enhance the detail and can confirm it is John Addison's work. Narrow Taylor style keys on the regulators are held in wooden blocks rather than the more usual metal plates and turning / style of drones are unmistakable
As for whether they are good buy depends upon overall condition and whether they are reeded and playing or are reeds missing and they have lain idle for some time. Regs removed from Main Stock and no sign of reeds but they could be in a box Some more clearer photographs would be useful - bass drone end appears to be bent.

Thanks very much for the informative reply. I know it's near impossible to say, but roughly what do you think they would be worth and if you were to take a gamble on buying a set like this, what would the max you'd risk on them?

A fair price is a difficult question to answer without having the pipes in front of me but better photographs with close ups of each part would be a help as ascertain if there are any faults. One suggestion would be to look at makers pricings to get an idea of what a new full set would cost. A S/H set saves joining a waiting list but is "Caveat Emptor" . What does the vendor want for them ? An important point to take into account is that John unfortunately passed away some years back so if they need attention i.e. reeds fitted and balanced you will have to find a maker who is willing to take the task on if you are not already a player and used to the fitting of reeds
Are you able to visit and inspect them to assess their condition and whether the reeds are with the instrument ? Do you already play the UP's ?

Sorry for taking so so long to get back to this. Basically the situation is that the pipes are being sold along with a lot of highland pipes which I'm interested but the seller wants to sell everything in one batch. He has no idea of value so wants me to offer for them. I have already told him what I'm willing to pay for the highland sets and know what I'm talking about with those but the Uilleann set is a mystery to me. What would you be willing to pay if you were to take a punt on them? A safe price that at worst, would be recoverable if selling them on? If you can base it on the assumption that they haven't been played in 5 or so years and have no reeds included. Even a rough guide would be good to have.

pricing right now would be for cost of wood only, put some reeds in it and real pricing can be determined. Bore and reed characteristics are so important to the worth and value of a set... Pakistani pipes are proof of this.